Theory, Stable theory, Set theory, Superstring theory, Theory of computation, Critical theory, Theory X and Theory Y, Computability theory, Grounded theory, M-theory, Theory (mathematical logic), Type theory, Theory-theory, String theory, Game theory, Model theory, Scientific theory, Number theory, Decision theory, Twistor theory, Theory of everything, Naive set theory, Information theory, Gauge theory, Götaland theory, Intuitionistic type theory, Systems theory, Probability theory, Economic Theory, Negotiation theory, Germ theory denialism, Unified field theory, Group theory, Dynamical systems theory, Fringe theory, Nordström's theory of gravitation, Queer theory, Descriptivist theory of names, Organizational theory, Practice theory, Circumscription theory

Molecular orbital theory, International relations theory, Theory of relativity, Communication theory, Morse–Kelley set theory, Theory of mind, Complexity theory and organizations, Cannon–Bard theory, C-K theory, Social theory, Scalar–tensor theory, Emission theory (relativity), Interpolation theory, Combinatorial game theory, Labeling theory, Drive theory, Lie theory, Outline of critical theory, Seiberg–Witten theory, Psychoanalytic theory, Theory (clothing retailer), Quare theory, Cell theory, Vapnik–Chervonenkis theory, Inter-universal Teichmüller theory, F-theory, Strain theory (sociology), BCS theory, Coding theory, Continuity theory, Caloric theory, Statistical theory, Causal theory of reference, Evolution as fact and theory, Quantum field theory, Lawvere theory, Labor theory of value, Twisted K-theory, Germ theory of disease, Theory of Colours, Conspiracy theory, Theory of art, Type II string theory, Valence bond theory, Path–goal theory, Equity theory, Actor–network theory, Sociological theory, Literary theory, Two-factor theory

Theory, Stable theory, Set theory, Superstring theory, Theory of computation, Critical theory, Theory X and Theory Y, Computability theory, Grounded theory, M-theory, Theory (mathematical logic), Type theory, Theory-theory, String theory, Game theory, Model theory, Scientific theory, Number theory, Decision theory, Twistor theory, Theory of everything, Naive set theory, Information theory, Gauge theory, Götaland theory, Intuitionistic type theory, Systems theory, Probability theory, Economic Theory, Negotiation theory, Germ theory denialism, Unified field theory, Group theory, Dynamical systems theory, Fringe theory, Nordström's theory of gravitation, Queer theory, Descriptivist theory of names, Organizational theory, Practice theory, Circumscription theory, Molecular orbital theory, International relations theory, Theory of relativity, Communication theory, Morse–Kelley set theory, Theory of mind, Complexity theory and organizations, Cannon–Bard theory, C-K theory, Social theory, Scalar–tensor theory, Emission theory (relativity), Interpolation theory, Combinatorial game theory, Labeling theory, Drive theory, Lie theory, Outline of critical theory, Seiberg–Witten theory, Psychoanalytic theory, Theory (clothing retailer), Quare theory, Cell theory, Vapnik–Chervonenkis theory, Inter-universal Teichmüller theory, F-theory, Strain theory (sociology), BCS theory, Coding theory, Continuity theory, Caloric theory, Statistical theory, Causal theory of reference, Evolution as fact and theory, Quantum field theory, Lawvere theory, Labor theory of value, Twisted K-theory, Germ theory of disease, Theory of Colours, Conspiracy theory, Theory of art, Type II string theory, Valence bond theory, Path–goal theory, Equity theory, Actor–network theory, Sociological theory, Literary theory, Two-factor theory, Theory of a Deadman, Zermelo set theory, Chern–Simons theory, Contract theory, Regality theory, Introduction to M-theory, Pattern theory, Yang–Mills theory, Temporal theory (hearing), Heterotic string theory, Bisexual theory, Graph theory, Matrix string theory, Miasma theory, Transition state theory, Representation theory, Subjective theory of value, Dual-coding theory, Postdevelopment theory, Set theory (music), Development theory, Perturbation theory, Control theory, K-theory, Transformational theory, Theories of humor, A Theory of Justice, Journal of Combinatorial Theory, Singularity theory, Ginzburg–Landau theory, Theory of forms, Power transition theory, Bow-wow theory, Potential theory, Dependency theory, Algorithmic learning theory, Optimality theory, ∞-Chern–Weil theory, Brans–Dicke theory, KK-theory, Liouville field theory, Supersymmetric theory of stochastic dynamics, Ring theory, Kripke–Platek set theory, Constructive set theory, Free-radical theory of aging, Structuration theory, Theory of change, Grand Unified Theory, Emission theory (vision), Rev Theory, Identity theory, Homotopy type theory, Automata theory, Journal of Approximation Theory, Kaluza–Klein theory, Contingency theory, World-systems theory, Social exchange theory, Feminist theory